Esterification: Acrylic acid esters

Acrylic acid esters in water-based coating, in particular butyl acrylates, are replacing more an more solvent borne paints. Typical commodity esters of acrylic acid are methyl-, ethyl-, n-butyl- and 2-ethylhexyl (2EHA)- esters. The strongest growth rates are expected with 2EHA, followed by butyl acrylate, methyl acrylate and ethyl acrylate.

Esters from alcohols like polyols, isobutanol, hexanol and iso-octanol are of less importance in the polymer industry.

 

Acrylic polymers are considered as non toxic and are gaining more and more importance. Typically these esters are catalysed at a temperature range between 70°C (160°F) and 130°C (265°F) to avoid the formation of the ethers from the alcohols.

 

Typical reaction

 

 

R1 = H acrylic acid - R2 = CH3 methacrylic acid

 

Structure of acrylic acid esters

 

 

Properties of acrylic acid and esters

 

 

Acrylic acid

Methyl acrylate

Ethyl acrylate

Butyl acrylate

2-Ethylhexyl acrylate

Molecular formula

C3H4O2

C4H6O2

C5H8O2

C7H12O2

C11H20O2

Molecular weight

72

86

100

128

184

Boiling point °C

141

80

100

148

216

Freezing point °C

13

< 76

< 72

< 65

< 76

Density (20/20°C)

1.049

0.957

0.923

0.900

0.866

 

 

CHEMRA is offering different catalysts with different porosities and permeability of the porous matrix to ensure a high degree of selectivity and a high space time yield. These catalysts can be used in fixed bed reactors but also in batch and slurry loop reactors. They are physically very stable to ensure a long catalyst life.

 

Recommended esterification catalysts

 

 

For more information about these new esterfication catalysts, please contact your CHEMRA sales representative.

 

Related page: Typical properties of TREVER®|LYST polymeric catalysts.